Spring
3
Grazing Guide
4
Spring
top grazing tips:
1 Take the
hassle out
of grassland
management
with a good
paddock
system
Grazing Guide
2 Choose
ryegrass
swards and
see the
benefits in
increased
sward
productivity
3 Avoid the
complexities,
concentrate
on the basics
and reap the
rewards
4 If you want
grass in
spring,
you need
to close
paddocks
on time in
autumn
Spring
5
how to cash in on grass
5 Don’t get in
over your
head, have
a planned
turn out
policy in
spring and
remember
to measure
grass
weekly
6 ’Graze
tight but
remember,
avoid
poaching at
all costs
7 Don’t let
swards get
too high
but also
don’t force
animals to
graze too
tight
8 Build a
grass bank/
reserve in
autumn, it
will allow
you graze
stock longer
and reduce
your winter
feed bill
9 Save
money;
use clover
to cut your
Nitrogen
bill
10Know the
fertility
status of
your farm;
look after
your grass
and it will
look after
you
Grazing Guide
6
Spring
Contents
 INTRODUCTION
Exploiting our grass-based advantage
 SPRING
Getting the turnout date right
Setting up the farm to utilise grass
Applying slurry in spring
Spreading nitrogen fertilizer
Spring rotation planner
Wet weather management
Managing grass supply Avoid wasting grass offered to grazing herd
The role of fertilizer in summer
Main Grazing Season (May to August)
Understanding your wedge
Target the autumn to reduce beef costs
Nitrogen applications
Autumn/winter grazing
Pre-grazing yield
60:40 rotation planner
Getting the meal feeding right
The best use of autumn grass
Wet weather management
Grazing Guide
11
14
18
20
22
26
8
Spring
Spring
28
30
32
38
40
50
52
54
56
58
62
64
68
9
spring
Grazing Guide
52
Autumn

THE
FACTOR

The key to mid-season or summer grazing is to ensure a constant
supply of high-quality grass ahead
of the animals.
High weight gains can be
achieved from a grass-only diet
once the correct pre-grazing yield
is offered and high levels of utilisation are continuously achieved.
Allowing pre-grazing yield to
exceed recommended levels leads to
a decline in grass quality and poor
bodyweight gain.
Finishing the first rotation on
time is critical for mid-season grass
supply and quality. It will ensure
that grass will be more easily managed in the second and subsequent
grazing rotations. Finishing the
first rotation too early will mean
animals are grazing on too short a
rotation from April onwards and
grass will run out. Finishing the
first rotation too late means that
grass will be in surplus, post-grazing residuals will be hard to achieve
Grazing Guide
Autumn
53
Nitrogen and slurry applications in autumn
On beef farms, grazing
stocking rates are quite varied but
generally low, which has a huge effect on feed demand. As the nitrate
directive deadline date for nitrogen
application is 15 September, farmers must decide now what level of
nitrogen application they will apply
to ensure sufficient grass growth for
the final three rotations.
Farmers with a high grass demand in October/November, who
have their nitrogen applications up
to date by August, should consider
applying a blanket application. The
amount to apply may vary, and will
depend on feed supply. Only blanket spread nitrogen if the farm is
under target for grass. Spreading
excess nitrogen in autumn is wasting money as the soil is naturally
releasing nitrogen.
Soil temperatures stay quite high
in September and grass responses
per kg N of between 10kg to 15kg
DM/ha have been recorded under
good growing conditions. Obviously, swards with more perennial
ryegrass will respond better to nitrogen and these should be targeted
DOs
DON’Ts
Apply slurry to paddocks with low soil
index
Use urea in dry periods
It may be possible to use urea when
spreading N in autumn
Apply nitrogen to clover rich pastures
Apply low levels of nitrogen rather than
missing N on paddocks
Miss nitrogen on paddocks if possible
Use light applications of slurry if available
DOs
DON’Ts
Walk the farm weekly
Walk farm fortnightly or less
frequently
Keep monitoring the
recovery of re-growths
Delay the reaction to high
grass growth
React quickly to increasing
grass growth
Let pre-grazing yields increase
Maintain pre-grazing yields
at 1400kg DM/ha (8cm)
Increase SR too much on
grazing area, by closing
paddocks for long-term silage
Graze paddocks out to 4cm
Graze paddocks to 5.0-5.5cm
Top only when necessary to
4-5cm
Extend rotation length >23
days
Keep rotation length at 18-21
days
Continually react to changes
in growth
Take out paddocks quickly
and quality will be affected for the
rest of the year.
The biggest problem on farms
is that the first rotation starts and
ends too late. The level of re-growth
recovery from late March to April
10th is the real indicator of the second rotation’s re-growth and how
much grass will be on the farm.
Avoid wasting grass offered to the
grazing herd
Too often on livestock farms there
is excessive grass offered to the
grazing herd. High grass utilisation is possible when pre-grazing
yields are at levels that the grazing
animals can graze out well.
The key focus during the main
grazing season is to offer high-quality/leafy material to the grazing
herds as often as possible through
the season.
Grazing animals respond positively to high-quality grass and it is far
easier for them to graze swards of
1,400 kg DM/ha (7-8cm) than swards
of 2,200kg DM/ha (10+cm).
29
The ideal pre-grazing yield for maximum animal performance is
1400kg DM/ha (8cm).
Under-grazing leads to a greater proportion of stem. This will
lower quality and animal performance.
Avoid turning stock into too heavy covers. React quickly to
surplus grass and save as baled silage.
Grazing Guide
Calendar
70
Calendar
71
FEBRUARY
Mon 10
Tues 11
Wed 12
Thurs 13
Fri 14
Mon 17
Tues 18
Wed 19
Thurs 20
Sat 15
Sun 16
Fri 21
Sat 22
Sun 23
Fri 28
Sat 29
Sun 30
Tues 1
Wed 2
Thurs 3
Fri 4
Sat 5
Sun 6
Tues 8
Wed 9
Thurs 10
Fri 11
Sat 12
Sun 13
Slurry spread- Slurry spread- Slurry spread- Slurry spread- Spread N
ing
ing
ing
ing
on dry farm
on heavy farm on heavy farm on heavy farm on heavy farm
Slurry spread- Slurry spreading
ing
on dry farm
Slurry spread- Slurry spread- Slurry spread- Slurry spread- Slurry spread- Slurry spread- Dividing pading
ing
ing
ing
ing
ing
docks
on dry farm
on dry farm
on dry farm
on dry farm
on dry farm
Mon 7
Mon 24
Get stock out
to grass
Get stock out
to grass
Get stock out
to grass
Get stock out
to grass
Get stock out
to grass
Spread N on
heavy farm
Spread N on
heavy farm
Mon 21
Tues 22
Wed 23
Thurs 24
Fri 25
Sat 26
Sun 27
Tues 25
Dividing paddocks
(heavy&dry
farms)
Wed 26
Dividing paddocks
(heavy&dry
farms)
Mon 31
TOP TIPS FOR THE MONTH
Slurry
Spread slurry on light covers that were closed up last in the
autumn. Apply 2500 gallons per acre – equivalent to spreading
0.5 bags of urea per acre. Remember to check the dates for your
spreading zone.
Paddocks
When dividing paddocks, avoid long narrow blocks. Try to keep
them as square as possible. 2ha paddocks are ideal for a 40-cow
herd. Position water troughs so that paddocks can be subdivided
during periods of peak growth.
Grazing Guide
Grazing to 4cm in the first rotation provides a platform for
excellent quality grass re-growth.
Grazing Guide
Dividing paddocks
(heavy&dry
farms)
monia volatilisation in warmer and
drier weather.
Approximately 85% of the economic fertilizer value of slurry is
due to its P and K content; 70% is K
(about five units of P and 38 units of
K per 1,000 gallons). Since application in autumn has little effect on P
and K utilisation, most of the slurry
value will still be utilised with autumn application.
The key issue with slurry at any
time of the year is to spread on
fields that need P and K. A question
that farmers should ask themselves
Grazing Guide
Getting it right during the main grazing season
JANUARY
Apply a blanket application of nitrogen if
required pre-September 15
for building autumn grass.
Swards on a long rotation with
nitrogen applied have the capacity
to achieve grass growth rates of up
to 40 to 50kg DM/ha/day through
September and October.
Autumn slurry
Timing of slurry application has
little effect on P and K utilisation
from slurry, provided application
does not take place in periods of
heavy rainfall that might cause
significant run-off losses.
Timing of application only has an
effect on N availability due to am-
Summer
Managing grass supply
Grass at a reasonable level of
utilisation (75%) costs about 7.5c/kg
utilisable dry matter compared with
first and second cut grass silage at
18.5c/kg and 18.2c/kg utilisable DM.
Grazed grass is the highest quality feed on the farm in spring, better
than silage and equivalent to concentrates. Based on these figures, it
is important to increase the grass
proportion in the diet of the beef
steer/heifer.
The key period to target is spring
for two reasons:
More expensive feeds such as
grass silage and concentrate can be
displaced by grazed grass.
Early spring grazing increases
grass quality in second, third, etc,
grazing rotations. Therefore, it
should be used as much as possible in the freshly calved suckler
cows or grazing steers’ diet. During
the early grazing season (February or March), a balance must be
found between feeding the animal
adequately, to sustain high animal
performance, and conditioning the
sward for the late spring/summer
grazing season. In the first rotation,
Joys of
Summer
28

Autumn
nitrogen
applications
 SUMMER
 AUTUMN 7
Thurs 27
Dividing paddocks
(heavy&dry
farms)
i
Dividing paddocks
(heavy&dry
farms)
Spread N
on dry farm
Mon 14
Spread N on
heavy farm
Spread N
on dry farm
Spread N
on dry farm
Tues 15
Wed 16
Spread N on
heavy farm
Spread N on
heavy farm
Spread N
on dry farm
Thurs 17
Spread N on
heavy farm
Mon 28
TOP TIPS FOR THE MONTH
Slurry
Heavy farms should spread slurry as soon as ground conditions allow.
Spread N
on dry farm
Fri 18
Spread N on
heavy farm
Get stock out
to grass on dry
farm
Sat 19
Spread N on
heavy farm
Get stock out
to grass
Sun 20
Spread N on
heavy farm
i
Early Nitrogen
Nitrogen should be applied on dry farms in early February with heavier farms getting out in midlate February. Spread at a rate of 23 units (0.5 bags of urea) per acre. Soil temperature should
be consistently above 5-6 degrees C. Do not spread if heavy rain is forecast.
Turnout
Dry farms should aim to get out to grass in mid February. Turnout out priority stock first.
Grazing Guide
Grazing Guide
 GRAZING +
Calendars
Nitrogen application throughout the year
Top tips to successfully grazing bulls Understanding how rye grass grows
Getting clover to work on the farm
83
84
88
92
7
Introduction
Exploiting our
grass-based
advantage

The potential to achieve high
levels of lifetime gain from grazed
grass gives Irish farmers a major
competitive advantage over many
of their European counterparts.
On average the cost of producing a
kilo of liveweight gain from grazed
grass is 80-85% less when compared
to an intensive concentrate based
system.
Ireland and Britain are the only
major beef producing regions
within Europe that are not heavily
dependent on intensive concentrate based feedlot systems to both
grow and finish animals. In most of
the major beef producing regions
across continental Europe when a
calf is weaned from its mother 100%
of the liveweight gain achieved
until slaughter is delivered from
concentrates. In Ireland on a well
managed grass based system there
is potential to deliver over 80% of
this gain from grazed grass.
Grazing Guide aims to help farmers ensure that they are exploiting
the full potential of grazed grass on
their farm, irrespective of production system or land type. Land
type is often seen as a barrier to
adopting good grassland management practices. However there are
still a number of simple steps that
farmers operating on heavy land
can take to improve grass growth
and utilisation. These are detailed
throughout the guide.
Getting cattle out to grass early
and ensuring an adequate supply of
good quality leafy grass is available throughout the grazing season
is key to obtaining high levels of
animal performance. The guide
breaks down the key management
steps that should be taken during
the spring, summer and autumn to
ensure this is achieved. The role of
clover, farm infrastructure, reseeding and soil nutrients in improving
grass growth and utilisation are
also covered in detail.
The authors of Grazing Guide
hope you find it beneficial in improving grassland management on
your farm and ultimately the profitability of your business.
Grazing Guide
8
Spring
spring
Joys of
Grazing Guide
Spring
9

Grass at a reasonable level
of utilisation (75%) costs about
7.5c/kg utilisable dry matter (DM)
compared with first and second cut
grass silage at 16.5c/kg and 18.2c/kg
utilisable DM.
Grazed grass is the highest
quality feed on the farm in spring,
better than silage and equivalent
to concentrates. Based on these
figures, it is important to increase
the grass proportion in the diet of
the beef animal.
The key period to target is spring
for two reasons:
More expensive feeds such as
grass silage and concentrate can be
displaced by grazed grass.
Early spring grazing increases
grass quality in second, third, etc,
grazing rotations. Therefore, it
should be used as much as possible
in the freshly calved suckler cow or
animal’s diet. During the early grazing season (February or March),
a balance must be found between
feeding the animal adequately, to
sustain high animal performance,
and conditioning the sward for the
late spring/summer grazing season.
Grazing Guide
Spring
10
Turnout during the main grazing season
DOs
DON’Ts
Maximise early spring grazing in the diet
of freshly calved suckler cows or priority
cattle
Allow stock remain on paddocks during
heavy rainfall resulting in poaching
Graze paddocks to 3.5cm to 4cm in the
first rotation
Use silage supply as a target for turnout
date
Implement on/off grazing or remove
stock from grass to prevent damage
Turn out all animals in the herd at once
In the first rotation, the key is to
graze paddocks out to 3.5 to 4cm and
set up paddocks for following rotations. By doing this, grass digestibility can be increased by 4 units in
May and June.
Across the country, the average
grazing season length is 220 days.
O b stac l es
Two of the main obstacles to achieving more days at grass, especially in
early spring, are poor soil conditions and periods of high rainfall. If
animals stay in the paddock, treading damage caused on heavier soils
or during periods of heavy rainfall
can result in reduced growth rates
Grazing Guide
(up to 20% lower) during subsequent grazing rotations. Allowing
animals access to pasture for a few
hours per day (on/off grazing) has
been shown to maintain high levels
of performance when compared
with grass silage based diets and
may be a strategy that can be implemented to extend grazing season
length. Traditionally, fattening diets
have been focused on high grass
silage combined with concentrates.
With core prices envisaged to stay
strong, beef farmers need to focus
on producing more carcase output
from pasture.
Animal performance increases,
of both finishing and store cattle,
from early turnout are substantial.
Research work has shown that animals turned out early to grass have
6% (+23kg) higher carcase weight
than animals turned out later in
spring. This could equate to close to
€60 to €70/head.
O utput
Benefits of
spring grazing
Lower feed costs
Higher daily gain
Fewer days to
finish/slaughter
Lower direct costs
(labour/feed/
machinery)
The increase in animal output
can be gained with good grazing
management and earlier turnout.
Not only is grass a lower cost feed
but the slurry generated is reduced
with a longer grazing season.
Achieving an extra day at grass
for the suckler cow is worth on average €1.50/cow/day. It is clear that
major efficiency gains can be made
with early turnout.
The goal with spring grazing is to
ensure that priority stock have first
access to grass, i.e. the stock that
will make most economic use of the
available pasture and reduce their
days to finish.
Unlike a dairy farm, a beef farm
has the opportunity to turnout
stock in smaller numbers. This can
be advantageous in targeting high
grass utilisation.
Spring
11
Perfect
timing
Getting
the turnout
date right

The aim in spring is to
increase the proportion of
grass in the diet of the grazing animal while at the same
time budgeting so that there is
enough grass until the start of
the second grazing rotation in
Continued on next page
Grazing Guide
12
Spring
Turnout during the main grazing season
early to mid-April.
Spring grazing should start in
February/March and continue until
mid-April. This varies from farm
to farm but the overriding aspect
of grazing management is to make
good use of spring grass.
P riority stoc k
All animals in the herd do not have
to be turned out together or at
the same time. Groups of animals
should be prioritised for early turnout, i.e. those that will benefit most
from high quality spring grass e.g.
young bulls, steers or beef heifers.
f irst rotation
The first grazing rotation should
be 40 to 50 days and finish around
10 April. This can be extended to
20 April in later growing or poorer
grass growing areas.
area to graze f irst
Graze 30% to 40% of the grazing
paddocks first to allow re-growths
to accumulate for the start of the
second rotation.
Grazing Guide
TURNOUT IS
TOO LATE
TURNOUT IS
RIGHT
TURNOUT IS
TOO EARLY
Too much grass
Cheaper feed costs
Run out of grass
Poor grass utilisation
Long first rotation
Very short first rotation
Poor grass growth
Utilise all early grass
Reduced grass growth
Short first rotation
Can close only what's
required for silage
No grass before early May
Too much area for first cut
silage
Priority stock to grass
No rest period for paddocks
High stocking rate on
grazing area
Maximise slurry use and
reduce chemical fertilizer
Silage cut will be late or
unable to make sufficient
quantities
Too cautious
Continuous measurement
No measurement
Slurry may not be spread
because of heavy covers
Poor utilisation of slurry
Spring
13
What are the advantages of finishing the first rotation on time
and the disadvantages of not finishing on time?
ADVANTAGES DISADVANTAGES
Have 6-7cm of grass (1,200+kg DM/ha) on first
grazed paddock
Too much grass on farm
Have the recommended 10 to 14 days grass on
the farm
Have 21-28 days grass on farm (double the
requirement)
High grass quality for second rotation due to
high grass utilisation in first rotation
Poor grass utilisation
Create a ‘wedge’: most grass will be in the paddock grazed first in spring, least in the paddock
grazed last
Post-grazing height too high; will result in
poor quality grass in subsequent rotations
Can close 30-40% of farm for silage
Will have to close >50% of farm to correct
grass surplus
Little topping required
One to two rounds of topping required
Higher weight gains
Poor weight gain
Silage ground should be grazed
early in the first rotation — this will
increase the available grazing area.
S trip grazing
If strip grazing or block grazing, a
maximum of three to four days per
block should be practised during
the first grazing rotation to protect
re-growth and ensure grass supply
for the second rotation.
P ost - grazing
Post-grazing heights of 3.5cm to
4cm should be targeted during the
first grazing rotation. Late turnout
with high cut grass covers will often
lead to poor grass utilisation and
subsequent poor pasture quality.
Turnout of animals should take
place during periods of dry weather,
with good underfoot conditions
— this will give animals an opportunity to ‘settle’ and start grazing
properly.
Early turnout will reduce the accumulation of surpluses during the
main grazing season.
Grazing Guide
Spring
14
Setting up the farm to utilise grass

S etting up
To ensure efficient grassbased beef production, a rotational
grazing system is essential. A rotational grazing system should have a
minimum of six and, ideally, eight
grazing divisions or paddocks per
grazing group on the farm.
W hy use a system?
Paddock grazing works on the basic
principle of `graze and rest’. Therefore, once a paddock is grazed, it is
allowed to undergo a rest period to
rejuvenate the sward leaf for the
following rotation. Grazing swards
with fast rotations in spring, (e.g. 12
to 15 days) will decrease grass production on the farm and place the
farm at a greater risk of running
into grass deficits.
A rotational paddock system can
reduce the risk of parasites, especially when calves are part of the
production system.
Grazing Guide
A rotational paddock
system can reduce
the risk of parasites,
especially when
calves are part of the
production system.
ÔÔGet a farm map with exact areas
of each paddock.
ÔÔNumber every paddock.
ÔÔAssign specific paddocks to stock,
i.e. cow paddocks, fattening stock
paddocks, leader follower paddocks.
ÔÔKeep a record of dates when
grazed, fertilised, topped and cut
for round bale silage.
ÔÔFind out the reseeding history
and soil fertility of each paddock.
ÔÔMaintaining a small number of
grazing groups will allow the total
number of paddocks required to
be maintained at a manageable
level. This can be done by grazing
steers and bulls together and by
mixed grazing of cattle and sheep
and leader/follower systems.
Roadways are an advantage as
they allow access to paddocks and
avoid soil damage.
Paddoc k sizes
Aim for equal divisions, avoiding
long, narrow divisions. The ratio of
field sides should be no more than
4:1 to prevent narrowing of paddocks.
The ideal size for a 40-cow suckler
herd is 2ha/paddock. Ensure that
each paddock has a number of access points. Water trough access is
equally important.
Temporary electric fencing
should be used to divide larger
fields to give the required paddock
size, especially when grazing silage
fields during the first rotation.
Divide paddocks so that at
least four or five grazings can be
achieved in spring and two or three
in autumn.
Water
A water supply in each grazing
division is necessary. Ideally, every
Spring
15
Grazing Guide
16
Spring
Positives of paddock systems and negatives of not using a paddock system
POSITIVES OF NEGATIVES
PADDOCK SYSTEM (WHEN PADDOCK
SYSTEMS ARE NOT USED)
Grazing management control
Lack of control
Higher grass production
Lower grass production
Ensure high utilisation
Poor utilisation
Improve grass quality
Lower grass quality
Greater access particularly in wet
weather
Poor access
Allow strip or block grazing
Control of grass budgeting
paddock should have a permanent
water supply.
Placing troughs across fences
reduces the number required.
If using a temporary wire to strip
or block graze, strategically place
troughs in the field so that animals
do not have to walk back over the
grazed area for water (see Example
2).
Keeping water troughs in the cen-
Grazing Guide
tre of the paddock allows for them
to be further split with temporary
fencing.
Alternatively, water troughs can
be fitted with a long length of water
piping and the water trough can
be moved between grazing areas
within the one paddock.
Water supply/pressure will often
dictate the size and type of water
trough used.
Farm roadways
Roadways are an
obvious advantage
as they allow easy
access to paddocks
and avoid soil
damage.
Water supply
Keeping water
troughs in the
centre of the
paddock allows
for them to be
further split with
temporary fencing.
Temporary
fencing
Temporary electric
fencing should
be used to divide
larger fields to
give the required
paddock size,
especially when
grazing silage
fields during the
first rotation
Spring
A.
Young steers
Beef heifers
Farm road network
B.
Young steers
Farm road network
Example 1
The map shows a section of a farm —
there are two groups of stock (e.g. young
steers and beef heifers) grazing the area
shown. Each group has eight grazing
divisions. The young steers graze the
eight paddocks light-shaded and the
beef heifers graze the eight dark-shaded
paddocks. The red lines show the road
network throughout the farm.
17
Beef heifers
Water Troughs
Strip Wires
Example 2
Diagram A shows two water troughs (in
blue) placed across the fence and serving
two paddocks.
The heavy dark lines show where strip
wires might be placed and how the water
troughs serve two divisions.
Diagram B shows a paddock that is
block grazed. One trough is placed in
the middle and services each of the four
grazing divisions.
Grazing Guide
Spring
18
Applying slurry in spring

Cattle slurry, as a valuable
source of N, P and K, should be applied on the fields that need it most
and at the time of year that will give
you the best response.
All of the P and K in slurry is
available to be utilised and fields
that are low in both of these nutrients need to be targeted to receive
slurry. On a lot of farms, this will be
the silage fields as this is where the
feed that eventually produces the
slurry comes from in the first place.
The time of year that slurry is
spread does not affect the availability or utilisation of P and K. This is
not the case with N.
Figure 1
2,500 gallons cattle
slurry per acre
(spring application)
Ideal conditions
Maximum utilisation rate
(24 units N/acre)
Average conditions
50% loss in utilisation
(12 units N/acre)
N in C att l e S lurry
Half of the nitrogen in cattle slurry
is in an organic form and the other
half is as ammonium, the very
same form of nitrogen that is in
purchased urea fertilizer.
It is the ammonium half that can
Grazing Guide
Poor conditions
Further 25% loss in
utilisation
(12 units N/acre)
replace bought in bagged N.
Similar to urea fertilizer there
are times of the year during which
you can expect to get the maximum
value of N from slurry and this is
very much weather dependent.
Ideal conditions for getting the
best nitrogen utilisation from cattle
slurry are:
ÔÔOvercast with very little sunshine
ÔÔSlight drizzle of rain
ÔÔLittle or no wind
Where the weather conditions are
only average, there is a 50% loss in
utilisation rate and where the conditions are poor, i.e. a dry, sunny day
with a strong breeze/wind, there is
a further 25% loss in utilisation rate
(Figure 1).
A good rule of thumb is that a day
that is very good for drying clothes
on a washing line is a bad day for
spreading slurry if you want to get
the maximum amount of N in it
utilised.
In order to get the maximum
value out of the N that is in cattle
slurry, the majority of it should
be spread in the spring when the
weather conditions favour it most.
When weather conditions are suitable, apply 2,500 to 3,000 gallons of
slurry to the paddocks/fields that
will not be grazed for at least six
weeks.
Paddocks that have heavy covers
of grass should not get slurry until
immediately after they are grazed.
When fields are grazed and closed
for silage, apply between 2,500 and
3,000 gallons of cattle slurry per
acre before applying any bagged
N. Reduce the amount of bagged N
spread by taking into account the
units that have been supplied in this
slurry.
There are three main advantages
with using a trailing shoe slurry
Spring
19
Spreading slurry
A trailing shoe allows slurry to be spread in a wider window,
increases N utilisation and allows slurry to be spread on
heavier covers.
DOs
DON’Ts
Spread most of the
slurry produced
on the farm in the
spring rather than
the summer
Spread slurry
when heavy
rain or frost is
forecast
Apply 2,500-3,000
gls of slurry to
ground that is going
to be grazed in six
weeks
Apply slurry to
heavy covers;
wait until they
are grazed first
TOP
TIPS
Spread slurry on
silage ground to
replace nutrients
and reduce
chemical N
requirement
Apply slurry on
dry sunny days
with strong
breeze
ÔÔOvercast with very little sunshine
ÔÔSlight drizzle of rain
ÔÔLittle or no wind
Spread slurry on
dull and slightly wet
days
Apply slurry on
top of bagged
fertiliser
spreader in the spring compared
with using a splash-plate spreader:
They widen the window of opportunity in getting slurry out on
farms with heavier soils.
They allow you to spread slurry
on paddocks/fields with heavier
covers of grass and still be able to
graze them six weeks later, i.e. less
contamination of grass.
They increase the utilisation rate
Ideal conditions for spreading slurry
of the N that is available in slurry
by up to 40%.
While there are advantages to
using a trailing shoe spreader in
comparison with more conventional
spreaders, at their current cost they
are still only justifiable in most
cases on a contractor scale. Individual farmers should negotiate the
best rate possible (per 1,000 gallons
spread).
Grazing Guide
Spring
20
Spreading nitrogen fertilizer

Nitrogen fertilizer can
provide a boost to spring grass
growth, allowing for more cattle to
be turned out earlier. Soil temperao
tures need to be at least 5 C before
there is an adequate response to it
and the date at which this occurs
can differ from year to year.
In good growing conditions, 1kg
of N has the ability to grow 10kg to
15kg of grass DM during February
while, in other years, there can be
little or no grass growth response to
the N due to prolonged cold weather
into March. The general recommendation has been to apply nitrogen
fertilizer six weeks before your
expected turnout date. With farms
that are moving towards turning
out smaller groups of cattle at intervals and starting with an earlier
turnout date, this recommendation
no longer applies and a more targeted approach is needed.
ÔÔPaddocks or fields that have heavy
Grazing Guide
Wait until soil
temperatures are
at least 5 degrees
and rising before
spreading N
covers of grass built up on them
(10cm+) from the previous autumn
and over the winter should be
grazed before applying N.
ÔÔPaddocks with little or no grass
covers should receive cattle slurry
first and N at a later date. These will
be the last to be grazed in the first
rotation.
ÔÔTarget your earliest N
applications on the paddocks
and fields that have the
greatest production potential –
predominately ryegrass swards –
with 5cm to 8cm of grass that have
good fertility (P, K & lime)
ÔÔApply no more than 23 units N per
acre for the first application.
ÔÔWait until soil temperatures are at
o
least 5 C and rising.
Urea is cheaper per kg N than
CAN and should be used in spring
applications wherever possible to
reduce costs.
The amount of N that should be
spread for first cut silage will depend on a number of factors:
ÔÔWhere slurry is applied first, the
requirement can be reduced by 9
units N per 1,000 gallons spread per
acre, e.g. 24 units N less when 2,500
to 3,000 gallons are spread.
ÔÔThe amount of ryegrass in the
sward to respond to N. Old pastures
with low levels of perennial
ryegrass should receive a maximum
of 80 units (from both slurry and N
fertilizer).
ÔÔNew reseeds will give a response
up to 100 units per acre.
ÔÔMost fields should be targeted to
receive 90 units in total.
ÔÔWhere fields have received N in
the weeks coming up to closing
for first cut silage, 1/3 of this N is
still assumed to be available and
this should also be taken off the
requirement.
Spring
21
Spreading nitrogen
DOs
DON’Ts
Apply N in
spring when soil
temperatures are
o
above 5 C
Apply to swards
with grass between
5 cm and 8 cm
Spread N on heavy
covers until after
grazing
Spread N on bare
paddocks. Spread
cattle slurry on
them instead
Apply more than 80
Apply 23 units per
units N per acre for
acre for the first
first-cut silage on
application
old pasture
Use urea rather than Apply more than 90
CAN to reduce costs. units N per acre for
first-cut silage on
most other swards
Take the amount of Spread chemical N
when there is heavy
N spread in cattle
slurry into account rainfall forecast
when applying
chemical N for silage
Turn cattle out late
Graze 40% of farm
as it will lead to
by March 17 and
grass accumulations
the rest by April
during the main
10. Dates can be
extended by 10 days growing season
on heavier farms
Grazing Guide